title: Ethanol-induced in vitro invasion of breast cancer cells: the contribution of MMP-2 by fibroblasts.
abstract: Ethanol is a tumor promoter and may promote metastasis of breast cancer. However, the underlying cellular/molecular mechanisms remain unknown. Overexpression and high activity of matrix metalloproteinase-2 (MMP-2) are frequently associated with metastatic breast cancers and serve as a prognostic indicator of clinical outcome. MMP-2 is predominantly expressed in stromal fibroblasts and plays a pivotal role in regulating the invasive behavior of breast tumor cells. We hypothesized that ethanol may enhance the invasion of breast tumor cells by modulating the activity of fibroblastic MMP-2. With in vitro models (HS68 and CCD1056SK human fibroblasts), we showed that ethanol at physiologically relevant concentrations (50-200 mg/dl) activated MMP-2; conversely, at a higher concentration (400 mg/dl), it inhibited the MMP-2 activity. Consistently, conditioned medium collected from ethanol (50-200 mg/dl)-exposed fibroblasts markedly enhanced the invasive potential of breast cancer cells and mammary epithelial cells overexpressing ErbB2/HER2 (BT474, SKBR-3 and HB2(ErbB2) cells) but had little effect on cells with low ErbB2 levels (BT20 and HB2 cells). In contrast, conditioned medium obtained from ethanol (400 mg/dl)-treated fibroblasts inhibited cell invasion. Selective inhibitors of MMP-2 (SB-3CT and OA-Hy) eliminated ethanol-stimulated invasion, indicating that the effect of ethanol was mediated by MMP-2. Ethanol activated conventional PKCs and JNKs in fibroblasts; inhibitors of PKC (Go6850 and Go6976) and JNKs (SP600125) significantly inhibited ethanol-mediated MMP-2 activation as well as cell invasion, indicating that PKCs and JNKs play a role in ethanol-induced MMP-2 activation and cell invasion in vitro. Thus, ethanol-promoted breast cancer cell invasion may be mediated by the modulation of fibroblastic MMP-2.
authors.affiliation: Department of Neurobiology and Anatomy, West Virginia University School of Medicine, Robert C. Byrd Health Sciences Center, Morgantown, WV, USA.
authors.forename: Moe Moe
authors.initials: MM
authors.lastname: Aye
authors.forename: Cuiling
authors.initials: C
authors.lastname: Ma
authors.forename: Hong
authors.initials: H
authors.lastname: Lin
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Bower
authors.forename: Richard C
authors.initials: RC
authors.lastname: Wiggins
authors.forename: Jia
authors.initials: J
authors.lastname: Luo
mesh_terms: D001681:Biological Assay; D001943:Breast Neoplasms / Q000473:pathology*; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000494:pharmacology*; D009361:Neoplasm Invasiveness / Q000503:physiopathology*; D014407:Tumor Cells, Cultured
chemical_list: D002492:Central Nervous System Depressants; D000431:Ethanol; D020778:Matrix Metalloproteinase 2