Expression and Subcellular Localization of E-Cadherin, .ALPHA.-Catenin, and .BETA.-Catenin in 8 Feline Mammary Tumor Cell Lines

Abstract

ABSTRACT. Protein expression and subcellular localization of E-cadherin, α-catenin, and β-catenin in 8 feline mammary tumor cell lines were examined by western blot analysis and fluorescence immunocytochemistry. A low E-cadherin expression was observed in FNNm cells. Furthermore, compared to other cell lines, two E-cadherin bands existed in FMC-p1 cells and were localized in the perinuclear region; distinct radial lines were observed in the cytoplasm. A low α-catenin expression was observed in FON-m cells, but there were no apparent abnormalities in its localization. In contrast, similar levels of β-catenin expression and cytoplasmic localization were observed in all cell lines.KEY WORDS: α-and β-catenin, E-cadherin, feline mammary tumor.J. Vet. Med. Sci. 69(8): 831-834, 2007 Cellular adhesion molecules are important for maintaining tissue structure and cell polarity, and are involved in cell movement and proliferation [13]. E-cadherin associates with a group of intracellular proteins termed catenins. α-Catenin serves as a bridge between E-cadherin and β-catenin, both of which connect with the microfilament cytoskeleton [20]. Disruption of normal cell-cell adhesion by alterations in cadherin-catenin molecules may contribute to enhanced migration and proliferation of tumor cells, thereby leading to invasion and metastasis [13].In human and experimental animal models, loss of E-cadherin expression was reported to cause cell migration or metastasis of tumor cells in breast cancers [11], gastric cancers [2], colorectal cancers [9], and prostate cancers [4]. Along with abnormalities of E-cadherin, the relationship between the disruption of the cell adhesion system and α-and β-catenin expressions was also reported in these cancers [7,8,17]. In addition to cell adhesion, β-catenin plays a role in the Wnt signaling cascade that regulates many cellular processes, including cell fate decisions and cell proliferation In cats, mammary tumors are the third common neoplasms, following skin tumors and lymphomas, and account for 12% of all tumors and 17% of the tumors in queens [15]. More than 80% of feline mammary tumors showed considerable malignancy along with rapid progression and metastasis at an early stage [12]. Since feline mammary tumors have malignant properties, investigating their carcinogenesis, tumor progression mechanisms, and the expressions of tumor related molecules is extremely essential. The purpose of this study was to investigate the expression and subcellular localization of E-cadherin, α-catenin, and β-catenin in 8 feline mammary tumor cell lines in order to evaluate the abnormalities of these cell adhesion molecules.In the present study, we used 8 feline mammary tumor cell lines, FKN-p, FMC-p1, FMC-p2, FMC-m, . Of these, 5 were established from a primary lesion, and 3 were established from a metastatic lesion in feline patients bearing spontaneous mammary tumors. Capital letters such as "FKN" indicate identical patients, and small letters such as "p" and "m", indicate primary and metastatic lesions, ...

Reduced Expression of E-cadherin and β-catenin and High Expression of Basal Cytokeratins in Feline Mammary Carcinomas With Regional Metastasis

“…6 Another study, using 8 cell lines from feline mammary tumors, showed the reduced expression of E-cadherin in cell lines obtained from a regional lymph node metastasis. 38 Our findings for E-cadherin confirm these previous reports: The highest percentage of reduction was observed in carcinomas with metastasis, while no reduction was observed in adenomas. The present study shows that a high percentage of carcinomas, mainly in those with regional metastasis, had a reduced expression of b-catenin, which suggests the presence of nonfunctional E-cadherin in some of the tumors that preserve the expression of this adhesion molecule.…”

“…1,5,10 However, few studies have been published on the expression of EMT markers (E-cadherin, b-catenin, or vimentin) in feline mammary carcinomas. 6,18,38 Those reports in the literature point to a high percentage of mammary carcinomas expressing vimentin as well as having a reduction of E-cadherin in the cell membranes of the neoplastic cells. Both findings could point to the existence of EMT phenomena in feline mammary carcinomas.…”

Immunohistochemical Expression of E-Cadherin and β-Catenin in Feline Mammary Tumours

“…Few studies have assessed the expression of adhesion molecules and their prognostic role in feline mammary tumours (Dias Pereira and G€ artner, 2003;Takauji et al, 2007). Progressive loss of membrane Ecadherin, together with abnormalities in its location, has been described in feline mammary carcinomas compared with benign tumours and hyperplastic or normal mammary tissue (Dias Pereira and G€ artner, 2003).…”

Tumor Cell Growth Inhibition and Cell Differentiation Analysis in a Canine Mammary Tumor Cell Line (MCM-B2) Treated with Four Chemical Reagents

“…They were then incubated with the appropriate first antibodies for 1 hr at RT, and subsequently incubated with horseradish phosphatase-conjugated antibodies against rabbit Ig (GE Healthcare) or mouse Ig (GE Healthcare) for 1 hr at RT. The signal was detected with an ECL Plus Western Blotting Detection System (GE Healthcare) [26].…”