NF-kappaB represses E-cadherin expression and enhances epithelial to mesenchymal transition of mammary epithelial cells: potential involvement of ZEB-1 and ZEB-2.
The transcription factor nuclear factor kappa B (NF-kappaB) is constitutively active in both cancer cells and stromal cells of breast cancer; however, the precise role of activated NF-kappaB in cancer progression is not known. Using parental MCF10A cells and a variant that expresses the myoepithelial marker p63 stably overexpressing the constitutively active p65 subunit of NF-kappaB (MCF10A/p65), we show that NF-kappaB suppresses the expression of epithelial specific genes E-cadherin and desmoplakin and induces the expression of the mesenchymal specific gene vimentin. P65 also suppressed the expression of p63 and the putative breast epithelial progenitor marker cytokeratin 5/6. MCF10A/p65 cells were phenotypically similar to cells undergoing epithelial to mesenchymal transition (EMT). MCF10A/p65 cells failed to form characteristic acini in three-dimensional Matrigel. Analysis of parental and MCF10A/p65 cells for genes previously shown to be involved in EMT revealed elevated expression of ZEB-1 and ZEB-2 in MCF10A/p65 cells compared to parental cells. In transient transfection assays, p65 increased ZEB-1 promoter activity. Furthermore, MCF10A cells overexpressing ZEB-1 showed reduced E-cadherin and p63 expression and displayed an EMT phenotype. The siRNA against ZEB-1 or ZEB-2 reduced the number of viable MCF10A/p65 but not parental cells, suggesting the dependence of MCF10A/p65 cells to ZEB-1 and ZEB-2 for cell cycle progression or survival. MCF10A cells chronically exposed to tumor necrosis factor alpha (TNFalpha), a potent NF-kappaB inducer, also exhibited the EMT-like phenotype and ZEB-1/ZEB-2 induction, both of which were reversed following TNFalpha withdrawal.
Chua
H L
HL
Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
Bhat-Nakshatri
P
P
Clare
S E
SE
Morimiya
A
A
Badve
S
S
Nakshatri
H
H
D015152:Blotting, Northern; D015153:Blotting, Western; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D024202:Electrophoretic Mobility Shift Assay; D004847:Epithelial Cells / Q000378:metabolism; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D042361:Mammary Glands, Human / Q000166:cytology / Q000378:metabolism*; D008648:Mesoderm / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000502:physiology*; D009361:Neoplasm Invasiveness / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D034741:RNA, Small Interfering / Q000494:pharmacology; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D000071799:Zinc Finger E-box-Binding Homeobox 1; D016335:Zinc Fingers
D015820:Cadherins; D018398:Homeodomain Proteins; D016328:NF-kappa B; D034741:RNA, Small Interfering; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1