title: The fibroblast growth factor-inducible 14 receptor is highly expressed in HER2-positive breast tumors and regulates breast cancer cell invasive capacity.
abstract: Genomic characterization is beginning to define a molecular taxonomy for breast cancer; however, the molecular basis of invasion and metastasis remains poorly understood. We report a pivotal role for the fibroblast growth factor-inducible 14 (Fn14) receptor in this process. We examined whether Fn14 and its ligand tumor necrosis factor-like weak inducer of apoptosis (TWEAK) were expressed in breast tumors and whether deregulation of Fn14 levels affected malignant behavior of breast cancer cell lines. Analysis of TWEAK and Fn14 in publicly available gene expression data indicated that high Fn14 expression levels significantly correlated with several poor prognostic indicators (P < 0.05). Fn14 expression was highest in the HER2-positive/estrogen receptor-negative (HER2(+)/ER(-)) intrinsic subtype (P = 0.0008). An association between Fn14 and HER2 expression in breast tumors was confirmed by immunohistochemistry. Fn14 levels were elevated in invasive, ER(-) breast cancer cell lines. Overexpression of Fn14 in weakly invasive MCF7 and T47D cells resulted in a marked induction of invasion and activation of nuclear factor-kappaB (NF-kappaB) signaling. Ectopic expression of Fn14tCT, a Fn14 deletion mutant that cannot activate NF-kappaB signaling, was not able to induce invasion. Moreover, ectopic expression of Fn14tCT in highly invasive MDA-MB-231 cells reduced their invasive capability. RNA interference-mediated inhibition of Fn14 expression in both MDA-MB-231 and MDA-MB-436 cells reduced invasion. Expression profiling of the Fn14-depleted cells revealed deregulation of NF-kappaB activity. Our findings support a role for Fn14-mediated NF-kappaB pathway activation in breast tumor invasion and metastasis.
authors.affiliation: Cancer and Cell Biology Division, The Translational Genomics Research Institute, 445 North Fifth Street, Phoenix, AZ 85004, USA.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Willis
authors.forename: Nhan L
authors.initials: NL
authors.lastname: Tran
authors.forename: Julie M
authors.initials: JM
authors.lastname: Chatigny
authors.forename: Nichole
authors.initials: N
authors.lastname: Charlton
authors.forename: Hong
authors.initials: H
authors.lastname: Vu
authors.forename: Sharron A N
authors.initials: SA
authors.lastname: Brown
authors.forename: Michael A
authors.initials: MA
authors.lastname: Black
authors.forename: Wendy S
authors.initials: WS
authors.lastname: McDonough
authors.forename: Shannon P
authors.initials: SP
authors.lastname: Fortin
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Niska
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Winkles
authors.forename: Heather E
authors.initials: HE
authors.lastname: Cunliffe
mesh_terms: D000256:Adenoviridae / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D016328:NF-kappa B / Q000378:metabolism; D009361:Neoplasm Invasiveness; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry; D000074050:TWEAK Receptor
chemical_list: D005346:Fibroblast Growth Factors; D016328:NF-kappa B; D018719:Erb-b2 Receptor Tyrosine Kinases; D018124:Receptors, Tumor Necrosis Factor; D011994:Recombinant Proteins; D000074050:TWEAK Receptor; C000613297:TNFRSF12A protein, human; C112971:fibroblast growth factor 14; C508053:ERBB2 protein, human