Significance of dysadherin and E-cadherin expression in differentiated-type gastric carcinoma with submucosal invasion. Hum Pathol. 2011;42:558-567. [PMID: 21239043 DOI: 10.1016/j.humpath.2010.08.016]

Dysadherin expression in prostatic adenocarcinoma and its relationship with E-cadherin and β-catenin

BACKGROUND

We analyzed immunoexpression of Dysadherin, E-cadherin and ß-catenin proteins in prostate.

METHODS

53 radical prostatectomy specimens were included. Dysadherin, E-cadherin and ß-catenin were evaluated in prostatic adenocarcinoma and in adjacent non-tumorous tissue, and correlated with clinicomorphological features in prostatic adenocarcinoma.

RESULTS

We report cytoplasmic/membraneous and nuclear staining for Dysadherin in prostatic tissue. Cytoplasmic/membraneous expression was stronger in prostatic adenocarcinoma when compared to adjacent non-tumorous prostatic tissue (p < 0.001).

Dysadherin positively correlated with T status (rho = 0.326, P = 0.017) and Grade Group (rho = 0.278, P = 0.044). We report no correlation with recurrence, surgical margins status, sPSA and N status. E-cadherin was negatively correlated with recurrence (rho = -0.297, P = 0.031), T status (rho = -0.430, P = 0.001), Grade Group (rho = -0.558, P < 0.001) and positive surgical margins (rho = -0.404, P = 0.003). ß-catenin negatively correlated with Grade Group (rho = -0.557, P < 0,001). No correlation was observed between Dysadherin and E-cadherin and Dysadherin and ß-catenin expression.

CONCLUSION

Our results suggest a potential role for Dysadherin in tumor progression. No significant correlation between Dysadherin and E-cadherin or ß-catenin indicates potential independence of Dysadherin in its regulatory role in prostatic adenocarcinoma.

Low expression of FXYD5 reverses the cisplatin resistance of epithelial ovarian cancer cells

OBJECTIVE

To investigate the effect of the downregulation of FXYD domain-containing ion transport regulator 5 (FXYD5) on the cisplatin resistance (CisR) of epithelial ovarian cancer (EOC) cells.

METHODS

A2780-CisR and SKOV3-CisR cells were obtained through repeated administrations of different cisplatin concentrations, and the half-maximal inhibition concentration (IC50) was calculated by MTT assays. After transfection with FXYD5 siRNA-1 and FXYD5 siRNA-2, the IC50 values of the A2780-CisR and SKOV3-CisR cells were also detected by the MTT method. Cell proliferation, migration, invasion and apoptosis were evaluated through 5-ethynyl-2'-deoxyuridine (EdU) DNA synthesis, wound healing, Transwell invasion and Annexin-V-FITC/PI dual-staining assays, respectively. qRT-PCR and Western blotting were conducted to detect mRNA and protein expression.

RESULTS

Compared with the sensitive parental cells, the A2780-CisR and SKOV3-CisR cells had increased IC50 and FXYD5 expression. FXYD5 siRNA reduced the IC50 value of cisplatin in the A2780-CisR and SKOV3-CisR cells and decreased the expression of ABCG2 (BCRP) and ABCB1 (MDR1). In addition, FXYD5 inhibition reduced the invasion and migration of the A2780-CisR and SKOV3-CisR cells, with upregulation of E-cadherin and downregulation of Snail and Vimentin. Both FXYD5 siRNA-1 and FXYD5 siRNA-2 inhibited the proliferation and promoted the apoptosis of the A2780-CisR and SKOV3-CisR cells with reduced Ki-67 and increased caspase-3.

CONCLUSION

FXYD5 downregulation may reduce the invasion, migration and EMT formation of EOC cells to increase their sensitivity to cisplatin chemotherapy by inhibiting cell proliferation and promoting cell apoptosis.

A strategy for generating cancer-specific monoclonal antibodies to aberrant O-glycoproteins: identification of a novel dysadherin-Tn antibody

Successful application of potent antibody-based T-cell engaging immunotherapeutic strategies is currently limited mainly to hematological cancers. One major reason is the lack of well-characterized antigens on solid tumors with sufficient cancer specific expression. Aberrantly O-glycosylated proteins contain promising cancer-specific O-glycopeptide epitopes suitable for immunotherapeutic applications, but currently only few examples of such antibody epitopes have been identified. We previously showed that chimeric antigen receptor T-cells directed towards aberrantly O-glycosylated MUC1 can control malignant growth in a mouse model. Here, we present a discovery platform for the generation of cancer-specific monoclonal antibodies targeting aberrant O-glycoproteins. The strategy is based on cancer cell lines engineered to homogeneously express the truncated Tn O-glycoform, the so-called SimpleCells. We used SimpleCells of different cancer origin to elicit monoclonal antibodies with selectivity for aberrant O-glycoproteins. For validation we selected and characterized one monoclonal antibody (6C5) directed to a Tn-glycopeptide in dysadherin (FXYD5), known to be upregulated in cancer and promote metastasis. While dysadherin is widely expressed also in normal cells, we demonstrated that the 6C5 epitope is specifically expressed in cancer.

FXYD5 Is an Essential Mediator of the Inflammatory Response during Lung Injury

The alveolar epithelium secretes cytokines and chemokines that recruit immune cells to the lungs, which is essential for fighting infections but in excess can promote lung injury. Overexpression of FXYD5, a tissue-specific regulator of the Na,K-ATPase, in mice, impairs the alveolo-epithelial barrier, and FXYD5 overexpression in renal cells increases C-C chemokine ligand-2 (CCL2) secretion in response to lipopolysaccharide (LPS). The aim of this study was to determine whether FXYD5 contributes to the lung inflammation and injury. Exposure of alveolar epithelial cells (AEC) to LPS increased FXYD5 levels at the plasma membrane, and FXYD5 silencing prevented both the activation of NF-κB and the secretion of cytokines in response to LPS. Intratracheal instillation of LPS into mice increased FXYD5 levels in the lung. FXYD5 overexpression increased the recruitment of interstitial macrophages and classical monocytes to the lung in response to LPS. FXYD5 silencing decreased CCL2 levels, number of cells, and protein concentration in bronchoalveolar lavage fluid (BALF) after LPS treatment, indicating that FXYD5 is required for the NF-κB-stimulated epithelial production of CCL2, the influx of immune cells, and the increase in alveolo-epithelial permeability in response to LPS. Silencing of FXYD5 also prevented the activation of NF-κB and cytokine secretion in response to interferon α and TNF-α, suggesting that pro-inflammatory effects of FXYD5 are not limited to the LPS-induced pathway. Furthermore, in the absence of other stimuli, FXYD5 overexpression in AEC activated NF-κB and increased cytokine production, while FXYD5 overexpression in mice increased cytokine levels in BALF, indicating that FXYD5 is sufficient to induce the NF-κB-stimulated cytokine secretion by the alveolar epithelium. The FXYD5 overexpression also increased cell counts in BALF, which was prevented by silencing the CCL2 receptor (CCR2), or by treating mice with a CCR2-blocking antibody, confirming that FXYD5-induced CCL2 production leads to the recruitment of monocytes to the lung. Taken together, the data demonstrate that FXYD5 is a key contributor to inflammatory lung injury.

The O-glycosylated ectodomain of FXYD5 impairs adhesion by disrupting cell-cell trans-dimerization of Na,K-ATPase β1 subunits

FXYD5 (also known as dysadherin), a regulatory subunit of the Na,K-ATPase, impairs intercellular adhesion by a poorly understood mechanism. Here, we determined whether FXYD5 disrupts the trans-dimerization of Na,K-ATPase molecules located in neighboring cells. Mutagenesis of the Na,K-ATPase β1 subunit identified four conserved residues, including Y199, that are crucial for the intercellular Na,K-ATPase trans-dimerization and adhesion. Modulation of expression of FXYD5 or of the β1 subunit with intact or mutated β1-β1 binding sites demonstrated that the anti-adhesive effect of FXYD5 depends on the presence of Y199 in the β1 subunit. Immunodetection of the plasma membrane FXYD5 was prevented by the presence of O-glycans. Partial FXYD5 deglycosylation enabled antibody binding and showed that the protein level and the degree of O-glycosylation were greater in cancer than in normal cells. FXYD5-induced impairment of adhesion was abolished by both genetic and pharmacological inhibition of FXYD5 O-glycosylation. Therefore, the extracellular O-glycosylated domain of FXYD5 impairs adhesion by interfering with intercellular β1-β1 interactions, suggesting that the ratio between FXYD5 and α1-β1 heterodimer determines whether the Na,K-ATPase acts as a positive or negative regulator of intercellular adhesion.

FXYD5 is a Marker for Poor Prognosis and a Potential Driver for Metastasis in Ovarian Carcinomas

Ovarian cancer (OC) is a leading cause of cancer mortality, but aside from a few well-studied mutations, very little is known about its underlying causes. As such, we performed survival analysis on ovarian copy number amplifications and gene expression datasets presented by The Cancer Genome Atlas in order to identify potential drivers and markers of aggressive OC. Additionally, two independent datasets from the Gene Expression Omnibus web platform were used to validate the identified markers. Based on our analysis, we identified FXYD5, a glycoprotein known to reduce cell adhesion, as a potential driver of metastasis and a significant predictor of mortality in OC. As a marker of poor outcome, the protein has effective antibodies against it for use in tissue arrays. FXYD5 bridges together a wide variety of cancers, including ovarian, breast cancer stage II, thyroid, colorectal, pancreatic, and head and neck cancers for metastasis studies.

Mitogen-activated protein kinase activator with WD40 repeats (MAWD) and MAWD-binding protein induce cell differentiation in gastric cancer

Background

Our previous proteomic analysis revealed that mitogen-activated protein kinase activator with WD40 repeats (MAWD) and MAWD-binding protein (MAWBP) were downregulated in gastric cancer (GC) tissues. These proteins interacted and formed complexes in GC cells. To investigate the role of MAWD and MAWBP in GC differentiation, we analyzed the relationship between MAWD/MAWBP and clinicopathologic characteristics of GC tissues and examined the expression of E-cadherin and pepsinogen C (PGC)—used as gastric mucosa differentiation markers—in MAWD/MAWBP-overexpressing GC cells and xenografts.

Methods

We measured MAWD, MAWBP, transforming growth factor-beta (TGF-beta), E-cadherin, and PGC expression in 223 GC tissues and matched-adjacent normal tissues using tissue microarray and immunohistochemistry (IHC) analyses, and correlated these expression levels with clinicopathologic features. MAWD and MAWBP were overexpressed alone or together in SGC7901 cells and then E-cadherin, N-cadherin, PGC, Snail, and p-Smad2 levels were determined using western blotting, semiquantitative RT-PCR, and immunofluorescence analysis. Alkaline phosphatase (AKP) activity was measured to investigate the differentiation level of various transfected cells, and the transfected cells were used in tumorigenicity assays and for IHC analysis of protein expression in xenografts.

Results

MAWD/MAWBP positive staining was significantly lower in GC tissues than in normal samples (P < 0.001), and the expression of these proteins was closely correlated with GC differentiation grade. Kaplan–Meier survival curves indicated that low MAWD and MAWBP expression was associated with poor patient survival (P < 0.05). The differentiation-related proteins E-cadherin and PGC were expressed in GC tissues at a lower level than in normal tissues (P < 0.001), but were upregulated in MAWD/MAWBP-overexpressing cells. N-cadherin and Snail expression was strongr in vector-expressing cells and comparatively weaker in MAWD/MAWBP co-overexpressing cells. MAWD/MAWBP co-overexpression inhibited Smad2 phosphorylation and nuclear translocation (P < 0.05), and AKP activity was lowest in MAWD/MAWBP coexpressing cells and highest in vector-expressing cells (P < 0.001). TGF-beta, E-cadherin, and PGC expression in xenograft tumors derived from MAWD/MAWBP coexpressing cells was higher than that in control.

Conclusions

MAWD and MAWBP were downregulated and associated with the differentiation grade in GC tissues. MAWD and MAWBP might induce the expression of differentiation-related proteins by modulating TGF-beta signaling in GC cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1637-7) contains supplementary material, which is available to authorized users.

FXYD6 is a new biomarker of cholangiocarcinoma

Members of the FXYD domain-containing ion transport regulator protein family, including FXYD3 and FXYD5, play an important role in the pathogenesis of numerous tumors. However, the correlation between the expression of FXYD6 and tumors remains poorly understood. In the current study, the expression of FXYD6 was examined immunohistochemically in 72 cholangiocarcinoma tissues and 30 distal normal bile duct tissues matched with the tumors. The results show that the positive expression rate of FXYD6 was significantly higher in cholangiocarcinoma than that in normal bile duct tissue (69 vs. 33.3%; P=0.002). Furthermore, the positive expression rate of FXYD6 in well- and moderately-differentiated cholangiocarcinoma was clearly higher than that in poorly-differentiated and mucinous cholangiocarcinoma (85.7 vs. 40%; P=0.000). However, there was no significant correlation between the expression of FXYD6 and gender (P=0.393), age (P=0.174), histological type (P=0.123), T stage (P=0.164), lymph node metastasis (P=0.343), perineural invasion (P=0.088) and tumor location (P=0.238). The results of this study indicate that FXYD6 may be a new biomarker for cholangiocarcinoma and may be associated with a favorable prognosis in this malignant disease.

Possible regulatory role of Snail in NF-κB-mediated changes in E-cadherin in gastric cancer

In the present study, we aimed to investigate the involvement of Snail in NF-κB-mediated changes of E-cadherin in gastric cancer. A total of 189 human gastric cancer tissues, and 32 normal gastric mucosal tissues were used to determine the expression levels of NF-κB, E-cadherin and Snail by immunohistochemistry. The correlation between the expression levels and patient clinicopathological data was analyzed. Human gastric cancer cell line SGC7901 was treated with the NF-κB inhibitor PDTC, and the expression levels of E-cadherin and Snail were investigated by qPCR and western blot. NF-κB, E-cadherin and Snail were all detected in normal gastric mucosa and cancer tissues of various differentiation statuses. However, the expression patterns of each protein were different. Strong expression of E-cadherin was detected in normal gastric mucosa, whereas its expression gradually declined in gastric cancer tissues, with weak expression observed in poorly differentiated gastric cancer tissues. In contrast, weak NF-κB and Snail expressions were present in normal gastric mucosa, while their expression levels gradually increased in gastric cancer tissues, with the strongest expression detected in poorly differentiated gastric cancers. The expression of E-cadherin was inversely correlated with that of Snail and NF-κB in the tissues tested. Blockade of NF-κB using its inhibitor PDTC led to a time-dependent reduction in Snail but a time-dependent increase in E-cadherin in SGC7901 cells. These results suggest that in human gastric cancer, loss of E-cadherin may be mediated through NF-κB-induced Snail upregulation. Further studies may reveal whether targeting the NF-κB-Snail-E-cadherin axis could be a useful approach for combating gastric cancer.

Expression of E-cadherin in angiomyolipoma

Angiomyolipoma is the most common member of perivascular epithelioid cell tumors that characteristically express myogenic and melanocytic markers. E-cadherin is a calcium-dependent cell-cell adhesion molecule that is repressed in epithelial to mesenchymal transition occurring in carcinomas. E-cadherin has not, thus far, been systematically studied in angiomyolipoma. We analyzed a series of 42 angiomyolipomas with E-cadherin and discussed its clinicopathologic significance. Forty-two cases of angiomyolipomas (35 renal, 5 hepatic, and 2 retroperitoneal) were examined histologically. E-cadherin was investigated immunohistochemically and compared with other significant markers found in angiomyolipoma in all cases. The percentages of tumors staining positively were E-cadherin (98%), smooth muscle actin (98%), actin (93%), HMB-45 (93%), Melan-A (90%), S-100 (38%), and CD117 (60%). The intensity of E-cadherin staining was moderate to strong in 30 cases (71%). E-cadherin stained both the cytoplasm and cell membrane of tumor cells, but membrane staining was stronger in the epithelioid tumor cells than in the spindle-shaped tumor cells. E-cadherin may serve as an additional diagnostic marker for angiomyolipoma. Angiomyolipoma should be included in the differential diagnosis of E-cadherin-positive tumors. Stronger membrane immunoreactivity for E-cadherin in epithelioid tumor cells is possibly related to constitution of their epithelioid architecture, but the pathogenetic significance of E-cadherin in angiomyolipoma remains to be further studied.

Role of the recently identified dysadherin in E-cadherin adhesion molecule downregulation in head and neck cancer

Dysadherin is a cancer-related cell membrane glycoprotein, recently identified, playing an important role in tumor progression and metastasis. In the present minireview article, we are focusing on the role of dysadherin in E-cadherin downregulation, the various expression patterns of the molecule in head and neck cancer as well as its potential role as a molecular target for future applications in diagnosis, clinical routine and prognosis of the disease.

ER-α36 promotes the growth of SGC-7901 cells in nude mice

AIM: To observe the effect of ER-α36 on the growth of SGC-7901 cells in nude mice.

METHODS: Utilizing lentivirus technology, we developed SGC7901 cell lines stably expressing ER-α36 siRNA vector (SGC7901-Low36) and ER-α36 expression vector (SGC7901-High36). Unmanipulated SGC7901 cells were used as controls (SGC7901-Control). These cells were subcutaneously injected into the nude mice to form SGC7901 transplantable tumors. The size and weight of the tumors were measured. Nuclear division was observed after HE staining, and the expression of Ki67 and E-cadherin was detected by immunohistochemistry.

RESULTS: Transplantable tumors formed in all nude mice. From day 16 to day 30, tumor size was highest in the SGC7901-High36 group, followed by the SGC7901-Control group, and the SGC7901-Low36 group had the least tumor size. There were significant differences (all P < 0.05) in tumor size between any two groups. On day 30, tumor weight was significantly higher in the SGC7901-High36 group than in the SGC7901-Control and SGC7901-Low36 groups (2.58 g ± 0.014 g vs 1.32 g ± 0.0245 g, 0.471 g ± 0.021 g; both P < 0.05). The number of nuclear division phases was significantly higher in the SGC7901-High36 group than in the SGC7901-Control and SGC7901-Low36 groups (42.33 ± 6.33 vs 28.5 ± 0.35, 12.5 ± 2.5; both P < 0.05). The expression of Ki67 was significantly higher in the SGC7901-High36 group than in the SGC7901-Control and SGC7901-Low36 groups (86.35 ± 5.23 vs 65.44 ± 4.56, 18.25 ± 2.56; both P < 0.05). The expression of E-cadherin in tumors in the SGC7901-High36 group was hardly seen, significantly lower than that in the SGC7901-Control and SGC7901-High36 groups.

CONCLUSION: ER-α36 may play an important role in gastric cancer cell growth and proliferation. ER-α36 may target tumor cells through adhesion molecules to promote tumor invasion and metastasis.