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1299304 
Journal Article 
Epidermal growth factor induces WISP-2/CCN5 expression in estrogen receptor-alpha-positive breast tumor cells through multiple molecular cross-talks 
Banerjee, S; Sengupta, K; Saxena, NK; Dhar, K; Banerjee, SK 
2005 
1 
Molecular Cancer Research
ISSN: 1541-7786 
Mol Cancer Res. 
3 
3 
151-162 
English 
15798095 
Epidermal growth factor (EGF) is a mitogen for estrogen receptor (ER)-positive breast tumor cells, and it has been proven that EGF occasionally mimicked estrogen action and cross-talks with ER-alpha to exert its activity. Therefore, the present study was undertaken to explore whether EGF is able to modulate the expression of Wnt-1-induced signaling protein-2/connective tissue growth factor/cysteine-rich 61/nephroblastoma overexpressed 5 (WISP-2/CCN5), an estrogen-responsive gene, in normal and transformed cell lines of the human breast and, if so, whether this induction is critical for EGF mitogenesis and what downstream signaling pathways are associated with this event. Here, we show that EGF-induced WISP-2 expression in ER- and EGF receptor-positive noninvasive MCF-7 breast tumor cells was dose and time dependent and that expression was modulated at transcription level. A synergism was seen in combination with estrogen. Moreover, small interfering RNA-mediated inhibition of WISP-2/CCN5 activity in MCF-7 cells resulted in abrogation of proliferation by EGF. The multiple molecular cross-talks, including the interactions between phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase signaling pathways and two diverse receptors (i.e., ER-alpha and EGFR), were essential in the event of EGF-induced WISP-2/CCN5 up-regulation in MCF-7 cells. Moreover, EGF action on WISP-2/CCN5 is restricted to ER- and EGFR-positive noninvasive breast tumor cells, and this effect of EGF cannot be instigated in ER-alpha-negative and EGFR-positive normal or invasive breast tumor cells by introducing ER-alpha. Finally, regulation of phosphorylation of ER-alpha and EGFR may play critical roles in EGF-induced transcriptional activation of WISP-2 gene in breast tumor cells. 
Blotting, Northern; Blotting, Western; Breast Neoplasms/metabolism; Butadienes/pharmacology; CCN Intercellular Signaling Proteins; Cell Line, Transformed; Cell Line, Tumor; Cell Proliferation; Cloning, Molecular; DNA, Complementary/metabolism; Dose-Response Relationship, Drug; Enzyme Inhibitors/pharmacology; Epidermal Growth Factor/physiology; Estrogen Receptor alpha/metabolism; Gene Expression Regulation, Neoplastic; Intercellular Signaling Peptides and Proteins/biosynthesis; MAP Kinase Signaling System; Microscopy, Confocal; Microscopy, Fluorescence; Neoplasm Invasiveness; Neoplasm Proteins/biosynthesis; Nitriles/pharmacology; Phosphatidylinositol 3-Kinases/metabolism; Phosphorylation; RNA/chemistry; RNA, Messenger/metabolism; RNA, Small Interfering/metabolism; Repressor Proteins; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Subcellular Fractions; Time Factors; Transcription Factors/biosynthesis; Transcription, Genetic; Transcriptional Activation; Transfection; Up-Regulation; 62229-50-9; 63231-63-0