Glucocorticoids induce CCN5/WISP-2 expression and attenuate invasion in oestrogen receptor-negative human breast cancer cells.
ABSTRACT CCN5 (cysteine-rich 61/connective tissue growth factor/nephroblastoma overexpressed 5)/WISP-2 [WNT1 (wingless-type MMTV integration site family, member 1)-inducible signalling pathway protein 2] is an oestrogen-regulated member of the CCN family. CCN5 is a transcriptional repressor of genes associated with the EMT (epithelial-mesenchymal transition) and plays an important role in maintenance of the differentiated phenotype in ER (oestrogen receptor)-positive breast cancer cells. In contrast, CCN5 is undetectable in more aggressive ER-negative breast cancer cells. We now report that CCN5 is induced in ER-negative breast cancer cells such as MDA-MB-231 following glucocorticoid exposure, due to interaction of the endogenous glucocorticoid receptor with a functional glucocorticoid-response element in the CCN5 gene promoter. Glucocorticoid treatment of MDA-MB-231 cells is accompanied by morphological alterations, decreased invasiveness and attenuated expression of mesenchymal markers, including vimentin, cadherin 11 and ZEB1 (zinc finger E-box binding homeobox 1). Interestingly, glucocorticoid exposure did not increase CCN5 expression in ER-positive breast cancer cells, but rather down-regulated ER expression, thereby attenuating oestrogen pathway signalling. Taken together, our results indicate that glucocorticoid treatment of ER-negative breast cancer cells induces high levels of CCN5 expression and is accompanied by the appearance of a more differentiated and less invasive epithelial phenotype. These findings propose a novel therapeutic strategy for high-risk breast cancer patients.
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ABSTRACT: Wnt-1-induced signalling pathway protein-2 (WISP-2)/connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed (CCN)5 is a member of the CCN family of growth factors and was identified as an oestrogen- inducible gene in the MCF-7 cell line. However, the role of WISP-2/CCN5 in breast carcinogenesis remains unclear. In this study, we examined the mechanism by which oestrogens regulate the expression of human (h) Wnt-1 induced signalling pathway protein (WISP-2)/CCN5. Real-time RT-PCR showed that hWISP-2/CCN5 mRNA transcripts level is upregulated by oestrogens in the oestrogen receptor-positive human breast cancer cell lines MCF-7, T47D and ZR-75.1. Cloning of a 1.9 kb fragment of the hWISP-2/CCN5 5'-flanking sequence and subsequent analysis of potential transcription factor-binding sites identified a functional oestrogen response element site located between - 581 and - 569 upstream from the oestrogen-induced transcription start site. Transient transfections of MCF-7 cells with the cloned fragment showed that oestradiol caused an increase in reporter gene activity, which was inhibited by anti-oestrogens ICI 182 780 and 4-hydroxytamoxifen. Chromatin immunoprecipitation analysis revealed an oestradiol-dependent recruitment of the oestrogen receptor alpha to the oestrogen- responsive region of the hWISP-2/CCN5 gene promoter. We also showed that endogenous CREB-binding protein (CBP) and p21(WAF1/CIP1) are recruited to the chromosomal hWISP-2/CCN5 promoter in MCF-7 cells in an oestrogen-dependent manner, suggesting that CBP and p21(WAF1/CIP1) participate in the oestrogen receptor alpha-mediated transcriptional control of the hWISP-2/CCN5 gene.Journal of Endocrinology 01/2007; 191(3):613-24. · 4.06 Impact Factor
- Annual Review of Biochemistry 02/1994; 63:451-86. · 27.68 Impact Factor
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ABSTRACT: In several cancers, including breast cancer, loss of E-cadherin expression is correlated with a loss of the epithelial phenotype and with a gain of invasiveness. Cells that have lost E-cadherin expression are either poorly invasive with a rounded phenotype, or highly invasive, with a mesenchymal phenotype. Most cells lacking E-cadherin still retain weak calcium-dependent adhesion, indicating the presence of another cadherin family member. We have now examined the expression of the mesenchymal cadherin, cadherin-11, in breast cancer cell lines. Cadherin-11 mRNA and protein, as well as a variant form, are expressed in the most invasive cell lines but not in any of the noninvasive cell lines. Cadherin-11 is localized to a detergent-soluble pool and is associated with both alpha- and beta-catenin. Immunocytochemistry shows that cadherin-11 is localized to the cell membrane at sites of cell-cell contact as well as at lamellipodia-like projections, which do not interact with other cells. These results suggest that cadherin-11 expression may be well correlated with the invasive phenotype in cancer cells and may serve as a molecular marker for the more aggressive, invasive subset of tumors. Cadherin-11 may mediate the interaction between malignant tumor cells and other cell types that normally express cadherin-11, such as stromal cells or osteoblasts or perhaps even with the surrounding extracellular matrix, thus facilitating tumor cell invasion and metastasis.Cancer Research 03/1999; 59(4):947-52. · 8.65 Impact Factor